1. Technical Field
The present disclosure is directed to improving the reliability of HVAC systems, and in particular, to improved systems, apparatus, and methods for monitoring HVAC compressor performance to identify potential or imminent failures before they can occur.
2. Background of Related Art
Air conditioning and heat pump systems, sometimes referred to as heating, ventilation, and air conditioning (HVAC) systems, employ the vapor-compression refrigeration cycle to cool or warm indoor air. In the case of an air-conditioning system, refrigerant gas is pressurized by a compressor and flows through a condensing coil. A fan blows air through the condensing coil to move heat from the refrigerant into the outside environment, causing the refrigerant to release heat and condense into liquid form. Refrigerant continues to an evaporator where it expands and vaporizes, absorbing heat from, and thereby cooling, indoor air blown through the evaporator by a second fan. In the case of a heat pump, the cycle is reversed whereby heat is moved from the outside environment to indoor air. The compressor and fans are typically driven by electric motors, which may be driven at a fixed speed or at a variable speed. Variable speed motors may be driven by a variable speed drive (VSD) which utilizes an inverter to vary the frequency of alternating current power delivered to the motor.
Over time, HVAC components are subject to wear and tear or other faults which can cause reduced efficiency, component failure, damage to other system components, or even system shutdowns. A technician responding to a service call faces a number of challenges when troubleshooting an HVAC system, particularly if the underlying problem is intermittent or temperature-related. For example, an HVAC system might fail on a hot and humid day, but if the technician arrives on a cooler day where the failure does not occur, it may be difficult to determine the cause of the failure and the proper remedy. In another scenario, a compressor nearing the end if its service life may be functional albeit at a lower efficiency, which increases operating costs to the homeowner in a manner which is not immediately apparent. In yet another scenario, a refrigerant leak can cause diminished performance, can damage compressor internals, and can be harmful to the environment.
An HVAC system which identifies potential problems before they occur would help maintain the overall effectiveness and reliability of the HVAC system, assist service technicians during troubleshooting, prevent customer dissatisfaction, and be a welcome advance in the art.